Novozym-435-catalyzed efficient preparation of (1S)-ethenyl and ethynyl 2,3-allenols and (1R)-ethenyl and ethynyl 2,3-allenyl acetates with high enantiomeric excess
摘要:
Novozym-435 (a form of Candida antarctica lipase B) was found to be an effective biocatalyst for the kinetic resolution of a variety of racemic I-ethenyl or ethynyl-substituted 2,3-allenols. The optically active 1-ethynyl-substituted 2,3-allenols can be subjected to Sonogashira coupling reactions and alkylations of terminal C-C triple bonds leading to the formation of 2,3-allenols, which cannot be directly prepared by Novozym 435-catalyzed kinetic resolution probably due to the steric hindrance. (C) 2003 Elsevier Ltd. All rights reserved.
PEARSON, N. R.;HAHN, G.;ZWEIFEL, G., J. ORG. CHEM., 1982, 47, N 17, 3364-3366
作者:PEARSON, N. R.、HAHN, G.、ZWEIFEL, G.
DOI:——
日期:——
Novozym-435-catalyzed efficient preparation of (1S)-ethenyl and ethynyl 2,3-allenols and (1R)-ethenyl and ethynyl 2,3-allenyl acetates with high enantiomeric excess
作者:Daiwang Xu、Zuyi Li、Shengming Ma
DOI:10.1016/j.tetasy.2003.09.048
日期:2003.11
Novozym-435 (a form of Candida antarctica lipase B) was found to be an effective biocatalyst for the kinetic resolution of a variety of racemic I-ethenyl or ethynyl-substituted 2,3-allenols. The optically active 1-ethynyl-substituted 2,3-allenols can be subjected to Sonogashira coupling reactions and alkylations of terminal C-C triple bonds leading to the formation of 2,3-allenols, which cannot be directly prepared by Novozym 435-catalyzed kinetic resolution probably due to the steric hindrance. (C) 2003 Elsevier Ltd. All rights reserved.
Preparation of functionally substituted allenes from methylacetylenes via propargylic lithium alanate or lithium borate intermediates